555 Basic Timer Circuit With LED on Output

This is the basic configuration for using the 555 Timer IC.  This circuit includes an LED on the output for visual feedback but the output can be connected to another circuit where a clock input is needed.

Hardware Needed

• (1) 555 Timer IC
• (1) LED
• (2) 330Ω Resistors
• (1)  µF Capacitor
• 9V Power Supply

Experimenting Further

The timing function is regulated by the resistors and capacitors.  Replace R3 with a different value resistor or even a variable resistor or potentiometer to see the results.
Change the duty cycle
Remove R2 and LED1 and connect to another circuit.

2 Transistor 2 LED Flasher

This is a 2 transistor astable multivibrator flashing LED Circuit.

Hardware Needed

• (2) 2n2222 NPN Transistors
• (2) LEDs
• (2) 330Ω Resistors
• (2) 10µF Capacitors
• 3V-9V Power Supply

Schematic